Since the early days of the iPhone, we've received a steady stream of complaints about how alerts are handled when you're on a call. Namely, you can have the phone to your ear, chatting away, when suddenly a text message comes in and the tone and/or vibrate goes off full blast into your ear and rattles through your skull. Since push notifications launched for 3rd party apps, especially the trumpeting horror that is Game Center, it's only gotten worse. If you're not used it to and expecting it, it can make you want to drop your phone and start stomping. That's only mild hyperbole, mind you, as that's exactly what several significant others have told us, with rage-filled eyes, after it happened to them for the first time.
While some people may want to make absolutely sure they don't miss an important alert while on a phone call, and are willing to pay the price in low-yield skull trauma, others would pay a significant amount of money for the option to turn it off.
So how could Apple cater to both types of users? The new Do Not Disturb Settings panel is tempting. But Do Not Disturb is model or timer based. A persistent settings wouldn't make sense there.
But there are already several similar, persistent switches in Settings > Sounds. You can already choose to turn off "Vibrate on Ring" and "Vibrate on Silence", but you may want those on at all times when you don't literally have your iPhone pressed to your ear. Adding an extra toggle, for "Mute All Alerts When on a Call" would be grand. "Notification sounds and vibrations will be temporarily muted when you’re on a call". (See the mock up at the top of this post.)
Apple could implement it using the same proximity sensor that currently tells iOS to turn off and disable multitouch when you've got your iPhone to your face.
It seems small, but it's the small things -- the buzzing flies and water droplets -- that drive us crazy in the end, and this seems like a rather simple one to fix.
Sure, adding "just another setting" is never the best answer. Except when it is.